ARTICLES, TIPS, TRAINING & GENERAL ADVICE

Boost Your Metabolic Rate

by Lisa Sabin, December 30, 2007

Weight Loss: Calories In vs. Calories Out

To lose fat, there must be an energy deficit. Energy expended exceeds energy intake. Weight loss occurs by decreasing the amount of calories consumed. This method tends to have a rebound effect with a regain of fat weight when the person returns to a normal diet.

How Resistance Training Effects Metabolism

To understand how resistance training effects metabolism, it’s helpful to think of the effects of exercise over a 24 hour period. Thermic Effect of Activity, accounts for about 15-30% of energy expenditure, Thermic effect of feeding accounts for about 10% or energy expenditure, and resting metabolic rate accounts for 60-75% of energy expenditure.

Strength training doesn’t burn as many calories during an exercise bout as aerobic exercise. However, strength training or resistance training causes a gradual increase in muscle mass which increases the basal metabolic rate (the calories required to maintain basic body functions throughout the day or night). As the metabolic rate increases, more calories are needed to perform daily functions.

Post-Exercise Energy Expenditure

EPOC, excess post-exercise oxygen consumption, refers to the calories expended (above resting values) after an exercise bout. This is the amount of oxygen the body is utilizing to return itself to its pre-exercise state. (Borsheim and Bahr, 2003) Studies have found that the magnitude and duration of EPOC is dependent on the intensity and duration of exercise. It can take 15 minutes to 48 hours for the body to recover to a resting state.

For every liter of oxygen consumed, approximately 5 calories are burned. EPOC was significantly longer following the highest intensity exercise. i.e. Cardiovascular training at 70-85% VO2 Max has a higher EPOC than exercising at 60-70% or 50%.

EPOC for resistance training was also longer following intense exercise bouts. In a study by Gilette et al. (1994), resistance training (5 sets, 10 exercises, 8-12 reps at 70% 1-rep max) elicited a greater EPOC response when compared to aerobic exercise (50% VO2 for 60 minutes) Circuit resistance training elicits an even greater EPOC response.

Putting It All Together

Although, there are variations in individual responses, additional caloric expenditure following exercise can have a positive effect over time and may contribute to long-term weight management. Cardiovascular training at or above 70% VO2,(almost every day) along with strength training or resistance training twice per week will have a positive effect on decreasing body fat and increasing lean body mass.

• Rob Parker, Resistance Training and Fat Loss, PT on The Net, Sept 1999
• Murphy, E. and Swartzkopf, R. 1992 Effect Pf standard set and circuit weight training on excess post-exercise oxygen consumption. Journal of Applied Sport Science Research, 6(2), 88-91
• Chantal A Vella, Ph.D. & Len Kravitz, Ph.D., Exercise Afterburn: Research Update

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